The US relies on natural gas for industrial, commercial and residential use. Because of this, natural gas pipeline safety is of utmost importance.
Almost 45 miles of pipeline were replaced in Massachusetts after a series of explosions and more than 60 fires occurred in September, 2018.
A teenager was killed, and approximately 25 people were injured. Nearly 18,000 customers lost power, and thousands were evacuated.
The company paid $23 million in claims to its customers.
What happened?
The pipeline’s serving utility company, Columbia Gas, was replacing cast iron pipes which were over a hundred years old in Lawrence, MA.
The gas lines became overpressurized.
This is just one example of the importance of natural gas pipeline safety.
Safe Use of Natural Gas
The use of natural gas is widely versatile, affordable, and environmentally friendly where carbon emissions are concerned.
Natural gas is not only used to in domestic stovetops; it is also found in heating and cooling systems, electricity generation, and in a huge array of industrial applications.
However, if its transportation system is not tended to, situations such as the one in Lawrence may develop.
How can we improve natural gas pipeline safety?
The importance of compressor valves in natural gas pipelines cannot be underestimated.
Understanding the flow of gas can lead to even safer and more efficient energy solutions.
Many turn a knob on their stovetop and see a blue flame ready to provide a heat source for dinner. But how did it reach the stovetop in the first place?
Becoming familiar with the path natural gas takes from extraction to processing to refining to distribution provides an appreciation for the role of compressor valves.
Pressure and the Process of Natural Gas Delivery
Natural gas is not manufactured; it is discovered. Sometimes located along with oil, natural gas is found in the Earth’s crust by geophysicists, geologists, and the drilling teams working with them.
Wells can be located on land or offshore. On average, they are usually around 5000 feet deep.
- The gas is summoned to the Earth’s upper crust by hydraulic fracturing.
- Once the well is solid, water and other fluids are then pumped into the well at high pressures to create fractures around the area where the gas has been pinpointed.
- The liquids lift the freed gas to the surface.
- The extracted gas is then separated into pipeline-quality gas and a mixture of gas liquids.
It is refined to clear out such impurities as sand, helium, hydrocarbons, water, sulfur, and non-usable gasses.
Transportation of Natural Gas
The remaining gas is then transported to reciprocating compressor stations and a system of pipes, or gathering lines.
The closer the subdivision of the pipelines is to the collection point, the larger the pipe is.
Once the gas has reached its final destination, it may have traveled thousands of miles from where it was extracted.
Pressure is always a main character in this process. Natural forces propel the gas from higher pressure to lower pressure.
In order to ensure the safety of staff members and those who live along the pipeline, each unit on the way is designed and built to withstand far more pressure than the system will ever experience, even in densely populated areas.
Usually, the pressure in the pipeline varies from between two hundred to fifteen hundred pounds per square inch.
Distribution to Compressor Stations
As the gas flows along the pipeline, it loses momentum and pressure.
Friction, differences in elevation, and remoteness from the extraction site contribute to slowing its movement.
The gas requires a boost to continue its journey to domestic or industrial consumers.
To provide it, every 50 to 60 miles, the gas reaches a compressor station.
Although it was processed at the extraction site, it may have collected new sand, particulates, or other impurities, so the gas is re-scrubbed.
Compressors now take charge of the gas, which has been flowing at about 30 miles an hour.
Sometimes, if the pressure of the gas is unusually low, it is compressed in more than one stage.
The majority of compressor stations are powered by the very natural gas it treats. Some compressor engines are turbine units; others are piston.
Reaching End Users
Once the gas leaves the compressor station with its increased pressure, it is transferred to end users.
As it travels, it may pass through more compressor stations, or it may be regulated with shut-off to regulate pressure. At times, relief valves are used to vent the natural gas into the atmosphere.
Before the gas is sent to a gas utility, it is sent to a gate station. Since natural gas is odorless, gate stations are where mercaptan is added.
Mercaptan is the overwhelmingly sulfur-concentrated smell that accompanies natural gas. It is blended in as a safety measure for consumers.
By now, the size of the pipes are at their smallest, and a pressure regulator is employed to bring its pressure down to under a quarter of a pound.
Since the air pressure in a domestic appliance or industrial device is lower than the gas pressure, it moves naturally and safely to its release point.
Maintaining Compressor Valves to Improve Natural Gas Pipeline Safety
In the movement of natural gas, well-maintained compressor valves at each step of the way help maintain natural gas pipeline safety and efficiency.
They are the center of each compressor, and they must be kept in good repair or reconditioned in order to provide reliable performance.
Since compressor valves are wear resistant, flame retardant, and made of durable materials, it may be difficult to eyeball when they might require servicing or replacement.
When they are used for movement of gas, they may be in constant use.
Paying attention to pressurization limits and the conditions in which the compressor valve operates are significant aspects of the monitoring process.
Since compressor valves may be present in various parts of the movement and supply of natural gas, they must work in efficient tandem with the machine of which they are a part.
Pressure checks, tests, and review of best practices can help to safeguard workers as well as consumers.
When the compressor valve operates efficiently and reliably, then entire process of providing natural gas, in all its dynamic and stationary phases, is beneficial to supplier and end user.